One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,6)(3,7,8,5)(9,10)(11,15)(12,16)(13,17)(14,18)(19,28)(20,26)(21,27)(22,29)(23,30)(24,31)(25,33)(32,38)(34,37)(35,39)(36,40)(1,3,4,8)(2,5,6,7)(9,11)(10,15)(12,19)(13,20)(14,21)(16,28)(17,26)(18,27)(22,32)(23,33)(24,34)(25,30)(29,38)(31,37)(35,40)(36,39)(9,12,14,23)(10,16,18,30)(11,19,21,33)(13,22,24,35)(15,25,27,28)(17,29,31,39)(20,32,34,40)(26,36,37,38)(9,13)(10,17)(11,20)(12,22)(14,24)(15,26)(16,29)(18,31)(19,32)(21,34)(23,35)(25,36)(27,37)(28,38)(30,39)(33,40) involution — undirected(13,24)(17,31)(20,34)(22,35)(26,37)(29,39)(32,40)(36,38) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.